The electrode materials are the most critical content for lithium‐ion batteries (LIBs) with high energy density for electric vehicles and portable electronics. Considering the high abundance, environmental friendliness, low cost, high capacity, and low operation potential of silicon‐based anode, it has been intensively studied as one of the most promising anode materials for high‐energy LIBs. However, the widespread application of silicon anode is impeded by the poor electrical conductivity, large volume variation, and unstable solid–electrolyte interfaces films. In the past decade, significant efforts have been demonstrated to tackle these major challenges toward industrial applications. Herein, the focus is on combining with advanced structure like nanostructure and composite with other materials, exploring various new polymer binders, improving electrolyte, different prelithiation strategies, and Si/graphite design to meet commercialization requirements, particularly summarized the progress on areal capacity, initial Coulombic efficiency, and cost. Finally, the guidelines and trends for practical silicon electrodes are presented based on the recent reports.

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Soft carbon is attracting tremendous attention as a promising anode material for potassium-ion batteries (PIBs) because of its graphitizable structure and adjustable interlayer distance. Herein, nitrogen/sulfur dual-doped porous soft carbon nanosheets (NSC) have been prepared with coal tar pitch as carbon precursors in an appropriate molten salt medium. The molten salt medium and N/S dual-doping are responsible for the formation of nanosheet-like morphology, abundant microporous channels with a high surface area of 436 m2 g–1, expanded interlamellar spacing of 0.378 nm, and enormous defect-induced active sites. These structural features are crucial for boosting potassium-ion storage performance, endowing the NSC to deliver a high potassiation storage capacity of 359 mAh g–1 at 100 mA g–1 and 115 mAh g–1 at 5.0 A g–1, and retaining 92.4% capacity retention at 1.0 A g–1 after 1000 cycles. More importantly, the pre-intercalation of K atom from the molten salts helps improve the initial Coulombic efficiency to 50%, which outperforms those of the recently reported carbon anode materials with large surface areas. The density functional theory calculations further illuminate that the N/S dual-doping can facilitate the adsorption of K-ion in carbon materials and decrease the ion diffusion energy barrier during the solid-state charge migration.

Metal sulfides are emerging as a promising anode material for sodium-ion batteries with high reversible capacities and fast reaction kinetics, but achieving long-cycling-life remains a great challenge. Here, taking cobalt sulfide as an example, its electrochemical sodium-ion storage failure phenomenon is first reported, which indicates that the battery cannot reach the cutoff voltage during charging. Detailed analyses demonstrate that such failure may originate from the dissolution and escape of polysulfide intermediates, further reacting with the released copper-ions from the current collector and inducing the occurrence of the shuttle effect. Based on the explored failure mechanism, a sulfur-doped carbon matrix with polar carbon sulfur bonds, which can firmly immobilize the dissolved polysulfides, is deliberately introduced into the Co 1−x S active particles (Co 1−x S/s-C) to improve their cycle stability. Consequently, the cycle life of the Co 1−x S/s-C anode for sodium-ion storage is extended from the original 125 to present 2000 cycles, even at high-rate current densities. Moreover, utilizing the carbon current collector instead of traditional copper can effectively delay the occurrence of the failure phenomenon. The present work promotes better fundamental understanding of the structural evolution of metal sulfide anodes during cycles, and the solution strategy can be extended to apply in other metal sulfides (ZnS, NiS).

Heterostructure anode material have been developed by engineering internal electric field to boost charge carrier transport for high-rate and high-capacity sodium ion storage.